finish event with log user participation

app/Policies/EventPolicy.php

@@ -58,7 +58,11 @@ class EventPolicy
         } else {
             $testedUser = $event->guests()->where('users.id', $user->id)->first();
             if ($testedUser !== null) {
-                return $testedUser->pivot->is_staff;
+                if($testedUser->pivot->is_staff) {
+                    return $testedUser->pivot->is_staff;
+                } else if (!$event->private) {
+                    return true;
+                }
             }
         }
         return false;
@@ -99,4 +103,20 @@ class EventPolicy
     {
         return false;
     }
+
+    /**
+     * Determine whether the guest can permanently delete invitation.
+     *
+     * @param  \App\User  $user
+     * @param  \App\Models\Event  $event
+     * @return mixed
+     */
+    public function participation(User $user, Event $event)
+    {
+        $testedUser = $event->guests()->where('users.id', $user->id)->first();
+        if ($testedUser !== null) {
+            return true;
+        }
+        return false;
+    }
 }